code: def _join_threads(self):
      for t in self.threads:
          t.join()
  
      try:
          exception_info = self.exception_queue.get_nowait()
      except queue.Empty:
          pass
      else:
          sys.excepthook(*exception_info)
          raise RuntimeError(
              "Exception found in one of the parties. Look at past logs."
          )
  
file_path: CrypTen/test/multithread_test_case.py
imports: import queue
  import sys
  import threading
  import unittest
  from functools import wraps
  from threading import Thread
  import crypten
label_desc: Use image node_id 6 for calling the MultiThreadTestCase obj's underlying member method code with example usage: obj._join_threads() without return types